Two sets of experiments (packing in calamansi juice ice, dipping in calamansi juice and packing in ordinary ice) conducted to determine the efficacy of calamansi (a type of citrus fruit similar to lemon) juice in prolonging the freshness of shrimps showed that calamansi juice inhibited the growth of micro-organisms on the flesh of shrimps, retarded proteolytic decomposition which was usually characterized by the development of fishness, blackening of the head and tail and loosening of shells, and inhibited development of strong off-odors.